Vaccinia virus D4 mutants defective in processive DNA synthesis retain binding to A20 and DNA.

ABSTRACT: Genome replication is inefficient without processivity factors, which tether DNA polymerases to their templates. The vaccinia virus DNA polymerase E9 requires two viral proteins, A20 and D4, for processive DNA synthesis, yet the mechanism of how this tricomplex functions is unknown. This study confirms that these three proteins are necessary and sufficient for processivity, and it focuses on the role of D4, which also functions as a uracil DNA glycosylase (UDG) repair enzyme. A series of D4 mutants was generated to discover which sites are important for processivity. Three point mutants (K126V, K160V, and R187V) which did not function in processive DNA synthesis, though they retained UDG catalytic activity, were identified. The mutants were able to compete with wild-type D4 in processivity

SUBMITTER: Druck Shudofsky AM 

PROVIDER: S-EPMC2976405 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature